Knob



FIG. 1 is a perspective view of a knob showing my new design, the undisclosed bottom is not part of the claimed design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a side view thereof, the opposite side being a mirror image of the side shown; and,

FIG. 4 is an end view thereof, the opposite end being a mirror image of the end shown.

The broken lines are included for the purpose of illustration and form no part of the claimed design. 

The ornamental design for a knob, as shown and described. 